Improvement in feeding sawdust to furnaces



A. J. EMLAW. Improvement in Apparatus for feeding Saw Dust to BoilerFurnaces.

N0. 120,052,v Pate1|ted'Oct.17,1871.

' ATE T ANDREW J. EMLAW, OF GRAND HAVEN, MICHIGAN.

IMPROVEMENT IN FEEDING SAWDUST TO FURNACES.

Specification forming part of Letters Patent No. 120,052, dated October17, 1871.

To all whom it may concern:

Be it known that I, ANDREW J. EMLAW, of Grand Haven, in the county ofOttawa and State of Michigan, have invented a new and useful Improvementin Apparatus for Feeding Sawdust to the Boiler-Furnaces of Saw-Mills,and I do declare that the following is a true and accurate descriptionthereof, reference being had to the accompanying drawing and to theletters of reference marked thereon, and being a part of thisspecification, in whichtube, showing the valve to one of the feed-chutesopened.

Similar letters of reference indicate corresponding parts in the severalfigures.

The nature of this invention relates to an ap paratus for automaticallyfeeding'the sawdust made in lumber-mills to the furnaces under theboilers, whereby the expense of handling and firing the sawdust issaved, while the larger pieces of refuse lumber, bark, &c., will becarried off after separation from the sawdust to a refuseburner detachedfrom the mill, or elsewhere, as preferred. The invention consists in thearrangement of an endless chain, the upper chord of which is caused totravel through a distributingpipe by a chain-wheel rotated from anyconvenient source of power, distributing the sawdust which sifts throughits links to feed-chutes pen dent from its bottom, discharging into thefurnace under each boiler, and in connection therewith a fan-blowerarranged to deliver a blast of air near the lower end of each chute toblow the sawdust into the furnace in volume regulated by a sliding gateat the top of each chute; also, in a peculiar spreading-plate in thefurnace under each boiler, to distribute the fuel blown in over thegrates; also, in providing the chutes with traps for delivering thesawdust on the hearth when required.

In the drawing, A represents an arch, in which are set two boilers,-B B.O are the fire-doors, and E the ash-doors of the front, of the usualconstruction. F is a distributing-box or pipe, carried across thefire-room above and in front of the arch, from which, opposite eachboiler, a feedchute, G, is led from its bottom to and through the frontof the arch, terminating in a spout or orifice under the front end ofeach boiler. H is a cut-off slide at the top of each chute, operated bya lever, I, and rod J', to regulate the opening from the pipe F; or thevalve-slide of each chute may be operated and adjusted independently, ifpreferred. K is a fan or rotary pressure blower, driven from anyconvenient line of shafting in the mill. From the blower the blast-tubeL is carried under and across the chutes and closed at the extremity. Abranch blast-tube or nozzle, L, is carried into each chute near itslower end. M is an endless chain, the construction of which is shown inFig. 3. The upper chord of this chain passes through-the pipe F, restingon its bottom, passing around the chain-wheels N N journaled across theends of said pipe, the former being rotated by the machinery of themill. 0 is a trap on the under side of each chute, which, when latchedopen, will permit a quantity of sawdust to fall on the hearth sufilcientto get up steam in the morning if the mill is not run nights.

If preferred, a fan-blower may be provided for each feed-chute, and, inpractice, where large nests of boilers are to be fired, it is foundnecessary to use several blowers, owing to the difficulty of adjustingthe blast to an equal division among the several chutes.

Any suitable carrier may be used to convey the sawdust from the saws tothe end of the feedbox E, and another may be used to convey the refusebark, 850., which will not sift through the chain to a refuse-burningfurnace, if one be used, or to a waste-heap, if not.

It will readily be seen that the chain carries the sawdust along to theopenings of the feedchutes, through which it falls to the furnace, butjust before entering it encounters the blast, and is driven in towardthe rear ends of the boilers. To arrest its course and at the same timeto distribute the fuel over the grates, I place a defleeting anddividing-plate, P, 1u1der each boiler, with its apex opposite the mouthof the chute, which effectually accomplishes the purpose.

I am well aware that blowers have been used for blowing sawdust intofurnaces; but in such cases heretofore the sawdust passed through theblower, which was liable to choke up; and I disclaim, broadly, theemployment of a blower for the purpose of blowing fuel into the furnace;but

What I do claim as my invention, and desire to secure by Letters Patent,is-

l. The construction and arrangement of a blower, K, and chute G, in themanner and fOl the purpose set forth.

2. The employment of the distributing-plates P under the boilers, inconnection with the feedchutes G, through which the fuel is blown intothe furnace, as and for the purpose set forth.

3. The arrangement of the chain M and chain- Wheels N N with relation tothe box F for distributing the fuel to the feed-chutes G, as set forth.

4. The arrangement of the slides H, lever I,

and rod J, with relation to the box F and chutes G, as and for thepurpose set forth.

5. The traps O in the chutes G, as'described, for the purpose specified.

ANDREW J. EMLAW. Witnesses:

H. F. EBERTs,

MYRoN H. OHURGH. (149)

